The field of the invention includes the various types of linear motors and so-called solenoids which provide straight line or circular motion are for a variety of applications, such as head positioning in disc memory drives, and pen positioning in plotters.
The closest prior art known is disclosed by U.S. Pat. No. 3,135,880 (Olson et al), which shows a device in FIG. 1 which is approximately the same as one-half of the device in this invention. As will be discussed infra, certain advantages are present in the approach in this invention.